The Philippine president, Rodrigo Duterte, has said he is ready to “declare war” against Canada over scores of containers holding Canadian household rubbish and electronic waste that have been sitting in his country’s ports for more than six years.

More than 100 containers of waste were shipped in batches from Canada to the Philippines in 2013 and 2014. Most of the containers remain in local ports, sparking protests from environmental activists. Philippine officials say they were falsely declared by a private firm as recyclable plastic scraps and have asked Canada to take the rubbish back.

“I will declare war against them. I will advise Canada that your garbage is on the way. Prepare a grand reception. Eat it if you want to,” Duterte said in a televised meeting with local officials late on Tuesday. “Your garbage is coming home.”

In a statement on Wednesday, the Canadian embassy in Manila said Canada was “strongly committed to collaborating with the government of the Philippines to resolve this issue.” The embassy also acknowledged a court order stipulating that the Canadian importer of the waste ship it back to the country.

The dispute has weighed heavily on the two countries’ relationship. In 2016, a Filipino judge ruled that Canada must take back the 1,300 tonnes of waste, which was brought to the Philippines by an importer and intercepted by the country’s customs bureau.

The Canadian prime minister, Justin Trudeau, has said in the past that he discussed the problem with Duterte.

Canadian regulations “prevented us from being able to receive the waste back in Canada”, Trudeau said in 2017. He said those legal barriers have been dealt with “so it is now theoretically possible to get it back”.

Lingering issues, however, including the consequences of the commercial transaction, which “did not involve government,” were delaying the resolution of the problem, he added.